It is known to use devices inside the vehicle for the purpose of monitoring the state of the tires, in particular for monitoring the air pressure in tires. These devices include a stationary device, which cooperates with a device that is moving together with the individual wheel of the vehicle, so that the air pressure can be monitored while the vehicle is in operation. The device moving together with the wheel senses the air pressure with the aid of a suitable arrangement and transmits the measured values by a clockless signal to the stationary device, which informs the driver if the air pressure drops below a specific value.
Current systems for tire monitoring are designed to monitor only the tire pressure and therefore often include a pressure sensor for measuring the pressure inside the tire; its measured values are transmitted to a stationary control device in the vehicle in a suitable manner, in particular in a wireless manner, by telemetry. More recent developments focus on systems that are integrated into the tire, in which the sensors, telemetry and energy production are vulcanized directly into the tire. Such systems require a pressure sensor and a signal-transmission arrangement. The known systems for determining the tire pressure are expensive and tend to be unreliable, especially in the aggressive environment of a vehicle tire.
As a result, there is the need for a more capable system for monitoring the tire pressure, which supplies meaningful information not only about the tire pressure but also about the material characteristics of the tire and possibly about the road characteristics.